If a (Richter) 4.0 moves it one-tenth of a foot, (about an inch), then a 5.0 moves it 1 foot, a 6.0 moves it 10 feet, a 7.0 moves it 100 feet. Etc. Go figure.

[Achtung!: N.S.F.W. ] Shake that thing like we in the city of sin, and
no fakin i know you see me shakin
and the way i break it down i got the whole world quakin
Off the Richter,
off the Richter,
off the Richter,
off the Richter,
off the Richter,
off the Richter steady are you ready ...

Cruz has zero sense at all. Her cavalear suggestion to close the bridge to traffic was hard core stupid and irresponsible.

If she had any sense or responsibility she would be "leading" as an elected official and find the means to take care of this vital infrastructure prior to any new spending on Milwaukie light rail or any other lame project.

I found my answer! A 0.2g seismic event is comparable to a Mercalli Scale VII or VIII (which is listed as being from 0.1g to 0.3g). Since we're in the middle of that on the "g" scale, we're looking at between those numbers.

Converting from Mercalli Scale VII gives us Richter scale 6. Converting from Mercalli Scale VII gives us Richter scale 6.5. So, going from the middle of those numbers, the documents suggest that the Sellwood bridge would suffer major damage from a quake larger than about 6.25 (based on the conversions above).

Now, the interesting thing I know about earthquakes is that there are more than one kind of earthquake. You have up and down motion and side-to-side motion. The side-to-side stuff is MUCH more dangerous, because structures aren't accustomed to lateral loading while they are used to vertical loading (think gravity). (And, thank you Smash Lab on Discovery Channel) I'd be willing to wager that the 0.2g (6.25 Richter) rating for the bridge is for an up-and-down quake since the rest of the seismic section warns about the bridge's weakness to lateral stresses.

If you held a meeting on the Sellwood Bridge with all the stakeholders, the city, county, metro and other kabitzers, the bridge would collapse before the opening invocation criticizing George Bush was completed.

That bridge will collapse before it is replaced ( or least they will ban all traffic and then start to get serious).

Why rush, none of those government types have to commute over that bridge.